<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>069-作用域的决定.html</title>
</head>
<body>
	
</body>
<script>
	var age = 18;
	function showAge(){
		var age = 20;
		return age;
	}
	console.log(age);//18
	console.log(showAge());//20
</script>
</html>